Is intelligence based on the gene.

Intelligence and Social Behavior - Genetically Predetermined?

The genome analysis carried out on a drop of blood immediately after the birth of little Vincent reveals everything: the boy's further development, peculiarities and diseases such as myopia and susceptibility to heart failure up to the cause of death and the age of death of around 30 years. This dystopian future, in which every person is defined solely by their genetic makeup, was the subject of the 1997 science fiction film "GATTACA". Fortunately, the genetic predetermination feared at the time has not been scientifically confirmed: Today it is clear that the environment has an influence on how we develop and how our faculties are expressed that should not be underestimated. On the other hand, a single typo in an important gene can mean the difference between healthy development and intellectual disability.

Professor Dr. Christian Schaaf, Managing Director of the Institute for Human Genetics at Heidelberg University Hospital, specializes in researching the genetic background of developmental disorders, intellectual disabilities and autism. At Medicine in the Evening on Wednesday, November 13, 2019, he will speak about the influence of genes and the contribution of the environment on human behavior and cognitive abilities, as well as present the possibilities and limits of human genetic diagnostics. The lecture begins at 7 p.m. in the lecture hall of the Kopfklinik, Im Neuenheimer Feld 400. University Clinic and Rhein-Neckar-Zeitung cordially invite all interested parties.

"Genes are not a one-way street"

When it comes to the question of the extent to which behavioral patterns, intelligence or mental illnesses are genetically predetermined, scientists like to take a look at people with identical genetic makeup who grew up under different conditions: identical twins who, for whatever reason, are Child were separated. Because the stronger the influence of the genes, the more similar the separated twins develop independently of each other. The result of these twin studies is reassuring: "We are not completely genetically determined: The environment offers a window of possibilities within which individual development can take place and genetic makeup can be varied," says Prof. Schaaf. As a doctor, he sees this primarily as an opportunity to be able to take therapeutic countermeasures even under unfavorable conditions. In particular, the cognitive abilities, e.g. in children with intellectual disabilities, can be favorably influenced within a certain range through optimal support. On the other hand, a child with good dispositions can lag far behind his possibilities due to a lack of support, isolation or traumatic experiences and even develop an autistic disorder under very unfavorable conditions.

The usually severe clinical picture of an autism spectrum disorder is caused by changes in the genetic make-up in around 70 to 80 percent of those affected. In the case of other mental illnesses and behavioral disorders such as depression, anxiety disorder and ADHD, the contribution of genes is rather small at around 20 percent, as Prof. Schaaf will explain in his lecture. Whether such a disorder or disease occurs is probably due to the sum of favorable and unfavorable genetic factors and environmental influences that interact individually in the individual. "Genes are not a one-way street - they are significantly influenced by social and societal factors," says the human geneticist.

Great advances in human genetic diagnostics

Will it ever be possible to modify behavior, intelligence, and sanity using genetic engineering? “Probably not”, suspects Schaaf: “Around 16,000 genes are active in the human brain. There are currently around 1,000 known genes whose changes play a role in intellectual disabilities. The interplay of all these factors is downright intimidatingly complex - the consequences of targeted changes cannot be foreseen at the current level. "

In contrast, thanks to new knowledge and methods, human genetic diagnostics have made great strides in recent years: "In the area of ​​intellectual disabilities, we now find a cause in around half of the children affected," explains the doctor. “Although in most cases this knowledge does not bring any immediate improvement in symptoms, it is usually an enormous relief for the parents: Having a diagnosis helps many to cope better with prejudices and even hostility. Because no, they didn't do anything wrong or treated their child badly. The disease is based on genetic causes and biological processes and not faults in upbringing. "